Paper sheet processing devices that perform various types of processing on paper sheets have heretofore been known in the art. For example, a paper sheet processing device as disclosed in Patent Document 1 performs deposit processing and dispense processing on paper sheets. This paper sheet processing device reads the serial numbers of given paper sheets. If any transport error has occurred, the device identifies, by its serial number, the paper sheet that has caused the transport error, and accepts, when some paper sheets are taken into the device again, only the paper sheet identified by that serial number.